While “user authentication”, which is authentication of a person who uses IT services, has been mainly performed at the time of authentication when the IT services are used, authentication of an object such as a terminal or a device has been performed as well as the user authentication due to the recent prevailing of Internet of Things (IoT) and the like. The authentication of the object is performed, for example, by transmitting identification information (serial number) of the terminal or the device to an authentication server.
A related technique is disclosed in Patent Literature 1. An authentication method disclosed in Patent Literature 1 determines, based on user identification information and identification information of a user-side device such as a smartphone transmitted from the user-side device and identification information of a setting-target device transmitted from the setting-target device, which is a device the user wants to associate with the user-side device, whether to associate the user-side device with the setting-target device.